ABSTRACT
Pedicle subtraction osteotomy (PSO) is a powerful technique that is used in the correction of fixed sagittal imbalance. It is a three-column osteotomy performed through a posterior approach and is typically used in cases where the fixed sagittal imbalance is greater than 10 cm. On average, it can provide approximately 30–35 degrees of correction in lumbar lordosis. The operative technique involves resecting a wide, V-shaped transpedicular wedge from one vertebral body, typically in the lumbar spine, which is then closed posteriorly to restore positive sagittal balance. This procedure involves a wide exposure with prolonged operative times and increased blood loss, with a high risk of medical and mechanical complications. Common mechanical complications include junctional failures, nonunions, and failure of instrumentation. In the case of symptomatic nonunion and/or construct failure, revision surgery should be considered.
